Ni-MH batteries are widely used in portable computers, cellular phones and new cordless appliances. It also has a bright prospect for being utilised as, a high performance battery for electrical vehicles (EV), hybride electric vehicles (HEV) and different tools because of its high energy density, high rate capability, long cycle life and environment friendly properties. For the application of Ni-MH battery in vehicles and tools it is necessary to further develop the fast charging and discharging kinetics in a wide temperature range. Efforts have been made in order to improve the electro-chemical charge and discharge kinetics of metal hydride electrode by surface treatments or AB-element substitution. Another alternative has been to vary the stoichiometry.
The present invention is based on the finding that unexpectedly improved properties of rechargeable nickel hydride batteries can be obtained by a new surface treatment method.